1. Field of the Invention
The present invention relates to a fuel supply control apparatus for an internal combustion engine and a fuel supply control method thereof, and, in particular, to a fuel supply control apparatus and a fuel supply control method for controlling an electric fuel pump, in an internal combustion engine which is provided with the electric fuel pump for pumping fuel to a fuel injection valve and a pressure regulator for regulating fuel pressure at set pressure.
2. Description of Related Art
Japanese Laid-open (Kokai) Patent Application Publication No. 9-126027 discloses an apparatus is provided with a sensor for detecting a flow amount of fuel to be returned to a fuel tank via a pressure regulator, the apparatus controls a drive current for a fuel pump based on the fuel flow amount detected by the sensor.
According to the apparatus as described above, an excessive fuel amount to be returned to the fuel tank via the pressure regulator can be reduced.
However, the apparatus provided with the sensor for detecting the flow amount has a problem in high cost performance since the sensor is disposed. Furthermore, the flow amount detected by the sensor pulsates, and thus, there is a problem in that the excessive fuel amount is hard to be controlled with high precision.